// import * as glMatrix from "gl-matrix/cjs/common";
// import {identity} from "gl-matrix/cjs/mat4";

let Vector3 = require('./Vector3');

var _v1 = new Vector3();
var _m1 = new Matrix4();
var _zero = new Vector3(0, 0, 0);
var _one = new Vector3(1, 1, 1);
var _x = new Vector3();
var _y = new Vector3();
var _z = new Vector3();

/**
 * @author mrdoob / http://mrdoob.com/
 * @author supereggbert / http://www.paulbrunt.co.uk/
 * @author philogb / http://blog.thejit.org/
 * @author jordi_ros / http://plattsoft.com
 * @author D1plo1d / http://github.com/D1plo1d
 * @author alteredq / http://alteredqualia.com/
 * @author mikael emtinger / http://gomo.se/
 * @author timknip / http://www.floorplanner.com/
 * @author bhouston / http://clara.io
 * @author WestLangley / http://github.com/WestLangley
 */

function Matrix4() {

    this.elements = new Float32Array([
        1, 0, 0, 0,
        0, 1, 0, 0,
        0, 0, 1, 0,
        0, 0, 0, 1
    ]);

    if (arguments.length > 0) {

        console.error('THREE.Matrix4: the constructor no longer reads arguments. use .set() instead.');

    }

}

Object.assign(Matrix4.prototype, {

    isMatrix4: true,

    set: function (n11, n12, n13, n14, n21, n22, n23, n24, n31, n32, n33, n34, n41, n42, n43, n44) {

        var te = this.elements;

        te[0] = n11;
        te[4] = n12;
        te[8] = n13;
        te[12] = n14;
        te[1] = n21;
        te[5] = n22;
        te[9] = n23;
        te[13] = n24;
        te[2] = n31;
        te[6] = n32;
        te[10] = n33;
        te[14] = n34;
        te[3] = n41;
        te[7] = n42;
        te[11] = n43;
        te[15] = n44;

        return this;

    },

    identity: function () {

        this.set(
            1, 0, 0, 0,
            0, 1, 0, 0,
            0, 0, 1, 0,
            0, 0, 0, 1
        );

        return this;

    },

    clone: function () {

        return new Matrix4().fromArray(this.elements);

    },

    copy: function (m) {

        var te = this.elements;
        var me = m.elements;

        te[0] = me[0];
        te[1] = me[1];
        te[2] = me[2];
        te[3] = me[3];
        te[4] = me[4];
        te[5] = me[5];
        te[6] = me[6];
        te[7] = me[7];
        te[8] = me[8];
        te[9] = me[9];
        te[10] = me[10];
        te[11] = me[11];
        te[12] = me[12];
        te[13] = me[13];
        te[14] = me[14];
        te[15] = me[15];

        return this;

    },

    copyPosition: function (m) {

        var te = this.elements, me = m.elements;

        te[12] = me[12];
        te[13] = me[13];
        te[14] = me[14];

        return this;

    },

    extractBasis: function (xAxis, yAxis, zAxis) {

        xAxis.setFromMatrixColumn(this, 0);
        yAxis.setFromMatrixColumn(this, 1);
        zAxis.setFromMatrixColumn(this, 2);

        return this;

    },

    makeBasis: function (xAxis, yAxis, zAxis) {

        this.set(
            xAxis.x, yAxis.x, zAxis.x, 0,
            xAxis.y, yAxis.y, zAxis.y, 0,
            xAxis.z, yAxis.z, zAxis.z, 0,
            0, 0, 0, 1
        );

        return this;

    },

    extractRotation: function (m) {

        // this method does not support reflection matrices

        var te = this.elements;
        var me = m.elements;

        var scaleX = 1 / _v1.setFromMatrixColumn(m, 0).length();
        var scaleY = 1 / _v1.setFromMatrixColumn(m, 1).length();
        var scaleZ = 1 / _v1.setFromMatrixColumn(m, 2).length();

        te[0] = me[0] * scaleX;
        te[1] = me[1] * scaleX;
        te[2] = me[2] * scaleX;
        te[3] = 0;

        te[4] = me[4] * scaleY;
        te[5] = me[5] * scaleY;
        te[6] = me[6] * scaleY;
        te[7] = 0;

        te[8] = me[8] * scaleZ;
        te[9] = me[9] * scaleZ;
        te[10] = me[10] * scaleZ;
        te[11] = 0;

        te[12] = 0;
        te[13] = 0;
        te[14] = 0;
        te[15] = 1;

        return this;

    },

    makeRotationFromEuler: function (euler) {

        if (!(euler && euler.isEuler)) {

            console.error('THREE.Matrix4: .makeRotationFromEuler() now expects a Euler rotation rather than a Vector3 and order.');

        }

        var te = this.elements;

        var x = euler.x, y = euler.y, z = euler.z;
        var a = Math.cos(x), b = Math.sin(x);
        var c = Math.cos(y), d = Math.sin(y);
        var e = Math.cos(z), f = Math.sin(z);

        if (euler.order === 'XYZ') {

            var ae = a * e, af = a * f, be = b * e, bf = b * f;

            te[0] = c * e;
            te[4] = -c * f;
            te[8] = d;

            te[1] = af + be * d;
            te[5] = ae - bf * d;
            te[9] = -b * c;

            te[2] = bf - ae * d;
            te[6] = be + af * d;
            te[10] = a * c;

        } else if (euler.order === 'YXZ') {

            var ce = c * e, cf = c * f, de = d * e, df = d * f;

            te[0] = ce + df * b;
            te[4] = de * b - cf;
            te[8] = a * d;

            te[1] = a * f;
            te[5] = a * e;
            te[9] = -b;

            te[2] = cf * b - de;
            te[6] = df + ce * b;
            te[10] = a * c;

        } else if (euler.order === 'ZXY') {

            let ce = c * e, cf = c * f, de = d * e, df = d * f;

            te[0] = ce - df * b;
            te[4] = -a * f;
            te[8] = de + cf * b;

            te[1] = cf + de * b;
            te[5] = a * e;
            te[9] = df - ce * b;

            te[2] = -a * d;
            te[6] = b;
            te[10] = a * c;

        } else if (euler.order === 'ZYX') {

            let ae = a * e, af = a * f, be = b * e, bf = b * f;

            te[0] = c * e;
            te[4] = be * d - af;
            te[8] = ae * d + bf;

            te[1] = c * f;
            te[5] = bf * d + ae;
            te[9] = af * d - be;

            te[2] = -d;
            te[6] = b * c;
            te[10] = a * c;

        } else if (euler.order === 'YZX') {

            let ac = a * c, ad = a * d, bc = b * c, bd = b * d;

            te[0] = c * e;
            te[4] = bd - ac * f;
            te[8] = bc * f + ad;

            te[1] = f;
            te[5] = a * e;
            te[9] = -b * e;

            te[2] = -d * e;
            te[6] = ad * f + bc;
            te[10] = ac - bd * f;

        } else if (euler.order === 'XZY') {

            let ac = a * c, ad = a * d, bc = b * c, bd = b * d;

            te[0] = c * e;
            te[4] = -f;
            te[8] = d * e;

            te[1] = ac * f + bd;
            te[5] = a * e;
            te[9] = ad * f - bc;

            te[2] = bc * f - ad;
            te[6] = b * e;
            te[10] = bd * f + ac;

        }

        // bottom row
        te[3] = 0;
        te[7] = 0;
        te[11] = 0;

        // last column
        te[12] = 0;
        te[13] = 0;
        te[14] = 0;
        te[15] = 1;

        return this;

    },

    makeRotationFromQuaternion: function (q) {

        return this.compose(_zero, q, _one);

    },

    lookAtInThreeJs: function (eye, target, up) {

        var te = this.elements;

        _z.subVectors(eye, target);

        if (_z.lengthSq() === 0) {

            // eye and target are in the same position

            _z.z = 1;

        }

        _z.normalize();
        _x.crossVectors(up, _z);

        if (_x.lengthSq() === 0) {

            // up and z are parallel

            if (Math.abs(up.z) === 1) {

                _z.x += 0.0001;

            } else {

                _z.z += 0.0001;

            }

            _z.normalize();
            _x.crossVectors(up, _z);

        }

        _x.normalize();
        _y.crossVectors(_z, _x);

        te[0] = _x.x;
        te[4] = _y.x;
        te[8] = _z.x;
        te[1] = _x.y;
        te[5] = _y.y;
        te[9] = _z.y;
        te[2] = _x.z;
        te[6] = _y.z;
        te[10] = _z.z;

        return this;

    },

    multiply: function (m, n) {

        if (n !== undefined) {

            console.warn('THREE.Matrix4: .multiply() now only accepts one argument. Use .multiplyMatrices( a, b ) instead.');
            return this.multiplyMatrices(m, n);

        }

        return this.multiplyMatrices(this, m);

    },

    premultiply: function (m) {

        return this.multiplyMatrices(m, this);

    },

    multiplyMatrices: function (a, b) {

        var ae = a.elements;
        var be = b.elements;
        var te = this.elements;

        var a11 = ae[0], a12 = ae[4], a13 = ae[8], a14 = ae[12];
        var a21 = ae[1], a22 = ae[5], a23 = ae[9], a24 = ae[13];
        var a31 = ae[2], a32 = ae[6], a33 = ae[10], a34 = ae[14];
        var a41 = ae[3], a42 = ae[7], a43 = ae[11], a44 = ae[15];

        var b11 = be[0], b12 = be[4], b13 = be[8], b14 = be[12];
        var b21 = be[1], b22 = be[5], b23 = be[9], b24 = be[13];
        var b31 = be[2], b32 = be[6], b33 = be[10], b34 = be[14];
        var b41 = be[3], b42 = be[7], b43 = be[11], b44 = be[15];

        te[0] = a11 * b11 + a12 * b21 + a13 * b31 + a14 * b41;
        te[4] = a11 * b12 + a12 * b22 + a13 * b32 + a14 * b42;
        te[8] = a11 * b13 + a12 * b23 + a13 * b33 + a14 * b43;
        te[12] = a11 * b14 + a12 * b24 + a13 * b34 + a14 * b44;

        te[1] = a21 * b11 + a22 * b21 + a23 * b31 + a24 * b41;
        te[5] = a21 * b12 + a22 * b22 + a23 * b32 + a24 * b42;
        te[9] = a21 * b13 + a22 * b23 + a23 * b33 + a24 * b43;
        te[13] = a21 * b14 + a22 * b24 + a23 * b34 + a24 * b44;

        te[2] = a31 * b11 + a32 * b21 + a33 * b31 + a34 * b41;
        te[6] = a31 * b12 + a32 * b22 + a33 * b32 + a34 * b42;
        te[10] = a31 * b13 + a32 * b23 + a33 * b33 + a34 * b43;
        te[14] = a31 * b14 + a32 * b24 + a33 * b34 + a34 * b44;

        te[3] = a41 * b11 + a42 * b21 + a43 * b31 + a44 * b41;
        te[7] = a41 * b12 + a42 * b22 + a43 * b32 + a44 * b42;
        te[11] = a41 * b13 + a42 * b23 + a43 * b33 + a44 * b43;
        te[15] = a41 * b14 + a42 * b24 + a43 * b34 + a44 * b44;

        return this;

    },

    multiplyScalar: function (s) {

        var te = this.elements;

        te[0] *= s;
        te[4] *= s;
        te[8] *= s;
        te[12] *= s;
        te[1] *= s;
        te[5] *= s;
        te[9] *= s;
        te[13] *= s;
        te[2] *= s;
        te[6] *= s;
        te[10] *= s;
        te[14] *= s;
        te[3] *= s;
        te[7] *= s;
        te[11] *= s;
        te[15] *= s;

        return this;

    },

    applyToBufferAttribute: function (attribute) {

        for (var i = 0, l = attribute.count; i < l; i++) {

            _v1.x = attribute.getX(i);
            _v1.y = attribute.getY(i);
            _v1.z = attribute.getZ(i);

            _v1.applyMatrix4(this);

            attribute.setXYZ(i, _v1.x, _v1.y, _v1.z);

        }

        return attribute;

    },

    determinant: function () {

        var te = this.elements;

        var n11 = te[0], n12 = te[4], n13 = te[8], n14 = te[12];
        var n21 = te[1], n22 = te[5], n23 = te[9], n24 = te[13];
        var n31 = te[2], n32 = te[6], n33 = te[10], n34 = te[14];
        var n41 = te[3], n42 = te[7], n43 = te[11], n44 = te[15];

        //TODO: make this more efficient
        //( based on http://www.euclideanspace.com/maths/algebra/matrix/functions/inverse/fourD/index.htm )

        return (
            n41 * (
                +n14 * n23 * n32
                - n13 * n24 * n32
                - n14 * n22 * n33
                + n12 * n24 * n33
                + n13 * n22 * n34
                - n12 * n23 * n34
            ) +
            n42 * (
                +n11 * n23 * n34
                - n11 * n24 * n33
                + n14 * n21 * n33
                - n13 * n21 * n34
                + n13 * n24 * n31
                - n14 * n23 * n31
            ) +
            n43 * (
                +n11 * n24 * n32
                - n11 * n22 * n34
                - n14 * n21 * n32
                + n12 * n21 * n34
                + n14 * n22 * n31
                - n12 * n24 * n31
            ) +
            n44 * (
                -n13 * n22 * n31
                - n11 * n23 * n32
                + n11 * n22 * n33
                + n13 * n21 * n32
                - n12 * n21 * n33
                + n12 * n23 * n31
            )

        );

    },

    transpose: function () {

        var te = this.elements;
        var tmp;

        tmp = te[1];
        te[1] = te[4];
        te[4] = tmp;
        tmp = te[2];
        te[2] = te[8];
        te[8] = tmp;
        tmp = te[6];
        te[6] = te[9];
        te[9] = tmp;

        tmp = te[3];
        te[3] = te[12];
        te[12] = tmp;
        tmp = te[7];
        te[7] = te[13];
        te[13] = tmp;
        tmp = te[11];
        te[11] = te[14];
        te[14] = tmp;

        return this;

    },

    setPosition: function (x, y, z) {

        var te = this.elements;

        if (x.isVector3) {

            te[12] = x.x;
            te[13] = x.y;
            te[14] = x.z;

        } else {

            te[12] = x;
            te[13] = y;
            te[14] = z;

        }

        return this;

    },

    getInverse: function (m, throwOnDegenerate) {

        // based on http://www.euclideanspace.com/maths/algebra/matrix/functions/inverse/fourD/index.htm
        var te = this.elements,
            me = m.elements,

            n11 = me[0], n21 = me[1], n31 = me[2], n41 = me[3],
            n12 = me[4], n22 = me[5], n32 = me[6], n42 = me[7],
            n13 = me[8], n23 = me[9], n33 = me[10], n43 = me[11],
            n14 = me[12], n24 = me[13], n34 = me[14], n44 = me[15],

            t11 = n23 * n34 * n42 - n24 * n33 * n42 + n24 * n32 * n43 - n22 * n34 * n43 - n23 * n32 * n44 + n22 * n33 * n44,
            t12 = n14 * n33 * n42 - n13 * n34 * n42 - n14 * n32 * n43 + n12 * n34 * n43 + n13 * n32 * n44 - n12 * n33 * n44,
            t13 = n13 * n24 * n42 - n14 * n23 * n42 + n14 * n22 * n43 - n12 * n24 * n43 - n13 * n22 * n44 + n12 * n23 * n44,
            t14 = n14 * n23 * n32 - n13 * n24 * n32 - n14 * n22 * n33 + n12 * n24 * n33 + n13 * n22 * n34 - n12 * n23 * n34;

        var det = n11 * t11 + n21 * t12 + n31 * t13 + n41 * t14;

        if (det === 0) {

            var msg = "THREE.Matrix4: .getInverse() can't invert matrix, determinant is 0";

            if (throwOnDegenerate === true) {

                throw new Error(msg);

            } else {

                console.warn(msg);

            }

            return this.identity();

        }

        var detInv = 1 / det;

        te[0] = t11 * detInv;
        te[1] = (n24 * n33 * n41 - n23 * n34 * n41 - n24 * n31 * n43 + n21 * n34 * n43 + n23 * n31 * n44 - n21 * n33 * n44) * detInv;
        te[2] = (n22 * n34 * n41 - n24 * n32 * n41 + n24 * n31 * n42 - n21 * n34 * n42 - n22 * n31 * n44 + n21 * n32 * n44) * detInv;
        te[3] = (n23 * n32 * n41 - n22 * n33 * n41 - n23 * n31 * n42 + n21 * n33 * n42 + n22 * n31 * n43 - n21 * n32 * n43) * detInv;

        te[4] = t12 * detInv;
        te[5] = (n13 * n34 * n41 - n14 * n33 * n41 + n14 * n31 * n43 - n11 * n34 * n43 - n13 * n31 * n44 + n11 * n33 * n44) * detInv;
        te[6] = (n14 * n32 * n41 - n12 * n34 * n41 - n14 * n31 * n42 + n11 * n34 * n42 + n12 * n31 * n44 - n11 * n32 * n44) * detInv;
        te[7] = (n12 * n33 * n41 - n13 * n32 * n41 + n13 * n31 * n42 - n11 * n33 * n42 - n12 * n31 * n43 + n11 * n32 * n43) * detInv;

        te[8] = t13 * detInv;
        te[9] = (n14 * n23 * n41 - n13 * n24 * n41 - n14 * n21 * n43 + n11 * n24 * n43 + n13 * n21 * n44 - n11 * n23 * n44) * detInv;
        te[10] = (n12 * n24 * n41 - n14 * n22 * n41 + n14 * n21 * n42 - n11 * n24 * n42 - n12 * n21 * n44 + n11 * n22 * n44) * detInv;
        te[11] = (n13 * n22 * n41 - n12 * n23 * n41 - n13 * n21 * n42 + n11 * n23 * n42 + n12 * n21 * n43 - n11 * n22 * n43) * detInv;

        te[12] = t14 * detInv;
        te[13] = (n13 * n24 * n31 - n14 * n23 * n31 + n14 * n21 * n33 - n11 * n24 * n33 - n13 * n21 * n34 + n11 * n23 * n34) * detInv;
        te[14] = (n14 * n22 * n31 - n12 * n24 * n31 - n14 * n21 * n32 + n11 * n24 * n32 + n12 * n21 * n34 - n11 * n22 * n34) * detInv;
        te[15] = (n12 * n23 * n31 - n13 * n22 * n31 + n13 * n21 * n32 - n11 * n23 * n32 - n12 * n21 * n33 + n11 * n22 * n33) * detInv;

        return this;

    },

    scale: function (v) {

        var te = this.elements;
        var x = v.x, y = v.y, z = v.z;

        te[0] *= x;
        te[4] *= y;
        te[8] *= z;
        te[1] *= x;
        te[5] *= y;
        te[9] *= z;
        te[2] *= x;
        te[6] *= y;
        te[10] *= z;
        te[3] *= x;
        te[7] *= y;
        te[11] *= z;

        return this;

    },

    getMaxScaleOnAxis: function () {

        var te = this.elements;

        var scaleXSq = te[0] * te[0] + te[1] * te[1] + te[2] * te[2];
        var scaleYSq = te[4] * te[4] + te[5] * te[5] + te[6] * te[6];
        var scaleZSq = te[8] * te[8] + te[9] * te[9] + te[10] * te[10];

        return Math.sqrt(Math.max(scaleXSq, scaleYSq, scaleZSq));

    },

    makeTranslation: function (x, y, z) {

        this.set(
            1, 0, 0, x,
            0, 1, 0, y,
            0, 0, 1, z,
            0, 0, 0, 1
        );

        return this;

    },

    makeRotationX: function (theta) {

        var c = Math.cos(theta), s = Math.sin(theta);

        this.set(
            1, 0, 0, 0,
            0, c, -s, 0,
            0, s, c, 0,
            0, 0, 0, 1
        );

        return this;

    },

    makeRotationY: function (theta) {

        var c = Math.cos(theta), s = Math.sin(theta);

        this.set(
            c, 0, s, 0,
            0, 1, 0, 0,
            -s, 0, c, 0,
            0, 0, 0, 1
        );

        return this;

    },

    makeRotationZ: function (theta) {

        var c = Math.cos(theta), s = Math.sin(theta);

        this.set(
            c, -s, 0, 0,
            s, c, 0, 0,
            0, 0, 1, 0,
            0, 0, 0, 1
        );

        return this;

    },

    makeRotationAxis: function (axis, angle) {

        // Based on http://www.gamedev.net/reference/articles/article1199.asp

        var c = Math.cos(angle);
        var s = Math.sin(angle);
        var t = 1 - c;
        var x = axis.x, y = axis.y, z = axis.z;
        var tx = t * x, ty = t * y;

        this.set(
            tx * x + c, tx * y - s * z, tx * z + s * y, 0,
            tx * y + s * z, ty * y + c, ty * z - s * x, 0,
            tx * z - s * y, ty * z + s * x, t * z * z + c, 0,
            0, 0, 0, 1
        );

        return this;

    },

    makeScale: function (x, y, z) {

        this.set(
            x, 0, 0, 0,
            0, y, 0, 0,
            0, 0, z, 0,
            0, 0, 0, 1
        );

        return this;

    },

    makeShear: function (x, y, z) {

        this.set(
            1, y, z, 0,
            x, 1, z, 0,
            x, y, 1, 0,
            0, 0, 0, 1
        );

        return this;

    },

    compose: function (position, quaternion, scale) {

        var te = this.elements;

        var x = quaternion._x, y = quaternion._y, z = quaternion._z, w = quaternion._w;
        var x2 = x + x, y2 = y + y, z2 = z + z;
        var xx = x * x2, xy = x * y2, xz = x * z2;
        var yy = y * y2, yz = y * z2, zz = z * z2;
        var wx = w * x2, wy = w * y2, wz = w * z2;

        var sx = scale.x, sy = scale.y, sz = scale.z;

        te[0] = (1 - (yy + zz)) * sx;
        te[1] = (xy + wz) * sx;
        te[2] = (xz - wy) * sx;
        te[3] = 0;

        te[4] = (xy - wz) * sy;
        te[5] = (1 - (xx + zz)) * sy;
        te[6] = (yz + wx) * sy;
        te[7] = 0;

        te[8] = (xz + wy) * sz;
        te[9] = (yz - wx) * sz;
        te[10] = (1 - (xx + yy)) * sz;
        te[11] = 0;

        te[12] = position.x;
        te[13] = position.y;
        te[14] = position.z;
        te[15] = 1;

        return this;

    },

    decompose: function (position, quaternion, scale) {

        var te = this.elements;

        var sx = _v1.set(te[0], te[1], te[2]).length();
        var sy = _v1.set(te[4], te[5], te[6]).length();
        var sz = _v1.set(te[8], te[9], te[10]).length();

        // if determine is negative, we need to invert one scale
        var det = this.determinant();
        if (det < 0) sx = -sx;

        position.x = te[12];
        position.y = te[13];
        position.z = te[14];

        // scale the rotation part
        _m1.copy(this);

        var invSX = 1 / sx;
        var invSY = 1 / sy;
        var invSZ = 1 / sz;

        _m1.elements[0] *= invSX;
        _m1.elements[1] *= invSX;
        _m1.elements[2] *= invSX;

        _m1.elements[4] *= invSY;
        _m1.elements[5] *= invSY;
        _m1.elements[6] *= invSY;

        _m1.elements[8] *= invSZ;
        _m1.elements[9] *= invSZ;
        _m1.elements[10] *= invSZ;

        quaternion.setFromRotationMatrix(_m1);

        scale.x = sx;
        scale.y = sy;
        scale.z = sz;

        return this;

    },

    makePerspective: function (left, right, top, bottom, near, far) {

        if (far === undefined) {

            console.warn('THREE.Matrix4: .makePerspective() has been redefined and has a new signature. Please check the docs.');

        }

        var te = this.elements;
        var x = 2 * near / (right - left);
        var y = 2 * near / (top - bottom);

        var a = (right + left) / (right - left);
        var b = (top + bottom) / (top - bottom);
        var c = -(far + near) / (far - near);
        var d = -2 * far * near / (far - near);

        te[0] = x;
        te[4] = 0;
        te[8] = a;
        te[12] = 0;
        te[1] = 0;
        te[5] = y;
        te[9] = b;
        te[13] = 0;
        te[2] = 0;
        te[6] = 0;
        te[10] = c;
        te[14] = d;
        te[3] = 0;
        te[7] = 0;
        te[11] = -1;
        te[15] = 0;

        return this;

    },

    makeOrthographic: function (left, right, top, bottom, near, far) {

        var te = this.elements;
        var w = 1.0 / (right - left);
        var h = 1.0 / (top - bottom);
        var p = 1.0 / (far - near);

        var x = (right + left) * w;
        var y = (top + bottom) * h;
        var z = (far + near) * p;

        te[0] = 2 * w;
        te[4] = 0;
        te[8] = 0;
        te[12] = -x;
        te[1] = 0;
        te[5] = 2 * h;
        te[9] = 0;
        te[13] = -y;
        te[2] = 0;
        te[6] = 0;
        te[10] = -2 * p;
        te[14] = -z;
        te[3] = 0;
        te[7] = 0;
        te[11] = 0;
        te[15] = 1;

        return this;

    },

    equals: function (matrix) {

        var te = this.elements;
        var me = matrix.elements;

        for (var i = 0; i < 16; i++) {

            if (te[i] !== me[i]) return false;

        }

        return true;

    },

    fromArray: function (array, offset) {

        if (offset === undefined) offset = 0;

        for (var i = 0; i < 16; i++) {

            this.elements[i] = array[i + offset];

        }

        return this;

    },

    toArray: function (array, offset) {

        if (array === undefined) array = [];
        if (offset === undefined) offset = 0;

        var te = this.elements;

        array[offset] = te[0];
        array[offset + 1] = te[1];
        array[offset + 2] = te[2];
        array[offset + 3] = te[3];

        array[offset + 4] = te[4];
        array[offset + 5] = te[5];
        array[offset + 6] = te[6];
        array[offset + 7] = te[7];

        array[offset + 8] = te[8];
        array[offset + 9] = te[9];
        array[offset + 10] = te[10];
        array[offset + 11] = te[11];

        array[offset + 12] = te[12];
        array[offset + 13] = te[13];
        array[offset + 14] = te[14];
        array[offset + 15] = te[15];

        return array;

    },

    perspective(fovy, aspect, near, far){
        let out = this.elements;
        var f = 1.0 / Math.tan(fovy / 2),
            nf;
        out[0] = f / aspect;
        out[1] = 0;
        out[2] = 0;
        out[3] = 0;
        out[4] = 0;
        out[5] = f;
        out[6] = 0;
        out[7] = 0;
        out[8] = 0;
        out[9] = 0;
        out[11] = -1;
        out[12] = 0;
        out[13] = 0;
        out[15] = 0;

        if (far != null && far !== Infinity) {
            nf = 1 / (near - far);
            out[10] = (far + near) * nf;
            out[14] = 2 * far * near * nf;
        } else {
            out[10] = -1;
            out[14] = -2 * near;
        }

        return this;
    },
    lookAt (eye, center, up){
        var EPSILON = 0.000001;
        let out = this.elements;
        var x0, x1, x2, y0, y1, y2, z0, z1, z2, len;
        var eyex = eye.x;
        var eyey = eye.y;
        var eyez = eye.z;
        var upx = up.x;
        var upy = up.y;
        var upz = up.z;
        var centerx = center.x;
        var centery = center.y;
        var centerz = center.z;

        if (Math.abs(eyex - centerx) < EPSILON && Math.abs(eyey - centery) < EPSILON && Math.abs(eyez - centerz) < EPSILON) {
            return this.identity();
        }

        z0 = eyex - centerx;
        z1 = eyey - centery;
        z2 = eyez - centerz;
        len = 1 / Math.hypot(z0, z1, z2);
        z0 *= len;
        z1 *= len;
        z2 *= len;
        x0 = upy * z2 - upz * z1;
        x1 = upz * z0 - upx * z2;
        x2 = upx * z1 - upy * z0;
        len = Math.hypot(x0, x1, x2);

        if (!len) {
            x0 = 0;
            x1 = 0;
            x2 = 0;
        } else {
            len = 1 / len;
            x0 *= len;
            x1 *= len;
            x2 *= len;
        }

        y0 = z1 * x2 - z2 * x1;
        y1 = z2 * x0 - z0 * x2;
        y2 = z0 * x1 - z1 * x0;
        len = Math.hypot(y0, y1, y2);

        if (!len) {
            y0 = 0;
            y1 = 0;
            y2 = 0;
        } else {
            len = 1 / len;
            y0 *= len;
            y1 *= len;
            y2 *= len;
        }

        out[0] = x0;
        out[1] = y0;
        out[2] = z0;
        out[3] = 0;
        out[4] = x1;
        out[5] = y1;
        out[6] = z1;
        out[7] = 0;
        out[8] = x2;
        out[9] = y2;
        out[10] = z2;
        out[11] = 0;
        out[12] = -(x0 * eyex + x1 * eyey + x2 * eyez);
        out[13] = -(y0 * eyex + y1 * eyey + y2 * eyez);
        out[14] = -(z0 * eyex + z1 * eyey + z2 * eyez);
        out[15] = 1;
        return  this;
    }
});


module.exports = Matrix4;
